Method of photographic duplicating



Feb. 7, 1956 H. c. PURDY METHOD OF PHOTOGRAPHIC DUPLICATING USINGPRINTOUT EMULsIoNs Filed March 7, 1947 :515.1 @fig/,m fxzof fo .ai cav/ATTORNEYS 'United- States ,Patent O METHOD OF PHOTOGRAPHIC DUPLICATINGUSING PRINT-GUT EMULSINS Harold C. Purdy, Friendship, N. Y., assignoi toHarold C. Purdy, Akron, Ohio, and Ellis H. Phillips, Bradford, Pa.,copartners Application March 7, 1947, Serial No. 733,067

Claims. (Cl. 955) This invention relates to the art of makingphotographic duplicates of originals such as printed matter or the like.The invention includes improvements in photographic duplicatingprocesses, improvements in materials suitable for such use, and alsoimprovements in the duplicate or copy as a finished product.

A particular object of the invention is to provide improvements in theart of making photographic duplicates whereby specialized knowledge andskill on the part of the maker of the duplicates is not required. Myinvention makes it unnecessary to use special printing fixtures,developing and iixing equipment, or other fixtures or equipment notcommonly found in business oliices.

At present there are innumerable devices and processes in use for makingduplicates or copies of printed matter, manuscripts, charts, anddrawings, that range from simple, inexpensive printing frames withaqueous or vaporous developing equipment, up to the well known photostatmachines which have elaborate and semi-automatic exposure and developingequipment, but which are far beyond the means or requirements of theusual business oiiice. The procedure in making such duplicates is, ingeneral, the same for all cases: i. e., an image, usually latent, isimpressed upon a light-sensitive emulsion by the action of light passingthrough the original or reliected from its surface; the sensitizedemulsion and its supporting base are removed from exposure to lightafter an interval of time which depends .upon the characteristics of theemulsion, the quality and intensity of the light, the ingredients of thedeveloping and fixing solutions or vapors, and the atmosphericconditions obtaining during the successive steps of the process; andupon removal from the action of light, the image is developed and fixed,or merely fixed as the case may be, by one of two general methods. Oneis to subject the exposed emulsion to the chemical action of a vapor,oftentimes that of mercury or ammonia, which action develops the latentimage and fixes it more or less permanently in the emulsion. Theequipment for controlling the vapor and handling the sensitized sheets,Without inconveniencing the personnel of the usual business oice,requires elaborate and special equipment which is not applicable to anyother office requirement. The other general method is to immerse theexposed print in a solution of chemical agents suitable for developingthe latent image, washing off the excess developing solution andby-products, and reimmersing in other chemical solutions suitable forfixing the image in the emulsion. This is followed by another washingand the subsequent drying of the print. Here, as in the vapor process,special equipment is required that is not applicable to any other oiiiceuse.

In the use of either the vapor or solution process, there is, inaddition to the necessary specialized equipment, a certain amount ofknowledge and skill required of the maker of the duplicate, whichlikewise is not applicable to any other requirement of the usualbusiness office. This special knowledge and skill is applied inmanipulat- 2,733,994 'Patented Feb. 7, 1956 ing and regulating themechanical features of the equipment, adjusting the time of exposure,and determmmg the time of development which varies with the degreeofexposure to light, ingredients of the developing and fixing agents, andchanges in concentration of the chemical agents as the processcontinues. This same knowledge and skill, when developed to a greaterdegree, becomes the art of the photographer. In fact, the processes,principles, and practices used in making duplicates are those used inphotography, and are so widely known and published that a more detaileddescription of them is superiluous here.

In general, it may be stated that my invention comprises an improvedphotographic print or duplicate of any original such as printed matteror the like, this print comprising an exposed layer of light-sensitiveprintingout emulsion permanently bonded to a layer of sheet material byan adhesive, the emulsion having been fixed by reaction of the emulsionwith the chemical fixing agents incorporated in the adhesive. Myinvention also contemplates the use of chemical toning agentsincorporated in the adhesive to produce the desired toning effect.

Another feature of my invention involves the use of a color gaugecarried by the sheet of transparent material which is coated with orcontains a light-sensitive printing out emulsion, this color gauge beingpreferably detachably secured to a marginal portion of the sheet or ilmof transparent material. This color gauge has the color and tone of theemulsion after the emulsion has been adequately exposed to light andaccordingly the use of this gauge makes it possible to produce uniformprints or duplicates by exposing the film to light until the color andtone of the emulsion matches the color and tone of the color gauge.

My invention also contemplates the production as an article ofmanufacture, of an unexposed print comprising a film of transparentmaterial carrying a light-sensitive printing out emulsion, the emulsionbeing covered by a layer of material having an exposed tacky surfacewhereby the unexposed print may be temporarily bonded to the surface ofthe original until the emulsion has `been exposed to light to thedesired extent; e. g., the emulsion carried by the iilm of transparentmaterial may be coated or covered with a layer of gelatin having itsexposed surface treated with glycerin to make it tacky. Y This articleof manufacture is described and claimed in my divisional applicationSer. No. 59,096, filed November 9, 1948, now Patent No. 2,686,122.

In general, it may be stated that my improved process comprises placingon a surface of the original a transparent iilm carrying alight-sensitive printing-out emulsion, exposing the lm to light until itacquires an image of the original of the desired intensity, removing thefilm from the original and bonding it to a layer of sheet materialcarrying an adhesive having incorporated therein chemical xing agentsfor fixing the emulsion. As indicated above, the process may alsoinclude the use of a color gauge carried by the emulsion coated film sothat any desired number of duplicate prints of uniform exposure can bereadily made by exposing each film to light until the image acquires acolor and tone matching that of the color gauge.

For convenience and clarity, certain terms used throughout thisspecification may be defined as follows:

Original is the printed page, manuscript, drawing, or the like, which isto be duplicated or copied.

Print (noun) when completed, becomes the duplicate of the original. Itmay be negative or positive, as these terms are used in the photographicart. lt comprises a light-sensitive element in, or on a suitablesupporting base.

Print (verb) to expose to the action of light.

Unexposed print has not been exposed to light,

Exposed print has been exposed to light, but in the case of a latentimage is undeveloped.

Developed print has been exposed to light and the latent image developedto a state of visibility. This term does not apply to printing-outprocesses.

Fixing or Fixation is the permanent cessation'of the printing anddeveloping processes in a developing-out emulsion, or the permanentcessation of printing 1n printing-out emulsions.

Developing-out process or material: the .action of light produces alatent image that becomes visible only by chemical development. t

Printing-out process or material: the action of light produces a visibleimage. It requires no development.

Toning is a chemical reaction producing desired changes in colors andtones. I

One objective of this invention being the diminution or elimination ofthe requirement of skill in the photographic art, I find that this isbest accomplished by using printingout emulsions instead ofdeveloping-out emulsions. it is common knowledge that the intensity ofartificial light in business oices is continually fluctuating andchanging because of the inherent characteristics of present day powersupply lines. Since the quantity of light required to produce an imagein any sensitized emulsion is represented by a factor-commonly calledthe time-intensity factorwhich is the resultant of the time of exposuremultiplied by the intensity of the light, and since the variations inthe intensity are indeterminate by any means available in the usualbusiness ofiice, the period of time required to produce a latent imagein a developing-out process cannot be foretold, and it can be determinedonly by specialized knowledge and a skillful use of a trial and errormethod.

A still greater degree of skill and knowledge is required to develop thelatent image in developing-out processes to a satisfactory degree ofcontrast between high-lights and shadows, which development partiallycompensates for the inaccurate determination of the time-intensityfactor. Thus, one objective of this invention would be defeated by theuse of such a developing-out process, and therefore I prefer to employ aprinting-out process.

The production of an image in a printing-out process is a function ofthe time-intensity factor to a far greater extent than in adeveloping-out process. in the latter, development accentuates the imagebegun by the action of light, whereas in a printing-out process, thelight alone produces the full visible image. A notable characteristic ofall printing-out emulsions referred to in this specification, is thatthe image progressively becomes darker as the time-intensity factor isincreased, and the degree of contrast between the high-lights andshadows of the finished print is a function of the quantity of lighthaving reacted upon the emulsion.

According to one embodiment of my invention, this degree of contrast maybe continuously observed by the maker of the print without regard to theelapsed time, without the use of instruments or other equipment, andwithout the use of a trial and error method. r:The depth of tone of theexposed print, or the color as the case may be with certain emulsions,is a measure of the quantity of light that has reacted upon theemulsion; and this tone or color can be predetermined for all values ofthe timeintensity factor. That is, a light of low intensity will requirea longer period of exposure than a light of greater intensity, but inall cases, equal time-intensity factorsor equal quantities of light-willproduce corresponding tones and colors in all prints having the samelight-sensitive emulsion. Thus the skill and knowledge required to makea duplicate with a printing-out emulsion is limited to an ability tocompare colors and tones.

Typical embodiments of my invention are illustrated in the accompanyingdrawings in which:

Fig. l in illustrations A, B, C and `D illustrates the various stages ofa process for making a duplicate of an original according to myinvention, illustration A representing an original such as a White orlight-colored sheet of paper with a black or dark-colored printedcharacter thereon, illustration B representing an unexposed printcomprising a transparent film placed over the original withlight-sensitive emulsion in contact with the original, illustration Crepresenting the original and print exposed to a source of light, andillustration D representing an exposed print removed from exposure tolight and placed in contact with a second sheet, one side of which iscoated with adhesive; and

Fig. 2 represents an unexposed print comprising a transparent filmcarrying a light-sensitive emulsion and a layer of material having atacky surface in contact with an original.

To exemplify one embodiment of my invention, the following procedure isused for making duplicates of opaque or translucent originals:Illustration A of Figure l, as stated above, represents an opaqueoriginal i which is a white or light colored sheet having a black ordark colored character 2 printed thereon. Upon this original i is placeda transparent or translucent film 3 having a light-sensitive emulsion 4on one side thereof, with said emulsion in contact with the surface ofthe original; the film becoming the duplicate or print. The print, whichmay adhere to the original by means described hereinafter, is exposed tothe action of a suitable light whereupon the light-sensitive element inthe emulsion changes color in proportion to the quantity of light actingupon it, and an image of printed character 2 is produced in emulsion d.

To facilitate the determination of the proper tone and color to whichthe duplicate is to be printed, and to further diminish the degree ofskill required of the maker of the duplicate, a strip of suitablematerial 8, illustration B of Fig. 2, is attached to or made a part ofsheet 3; the color and tone of material 8 being that of the deepest toneto which the image is to be printed. The color and tone of the indicatorstrip 8 may be different for different emulsions, but in all cases itcan be correctly pre-determined for the emulsion to which it is attachedor made a part ol".

When the color or tone or both, as the case may be, corresponds to thecolor and tone of indicator strip 8 which is attached to or made a partof sheet 3, a sufficient quantity of light has acted upon the sensitizedemulsion and the desired contrast will have been produced between theimage and the background. The plint is then removed from exposure tolight and from contact with the original, and is laid upon a hatsurface, such as a desk top, with emulsion 4 facing upwards. A secondsheet 5, which has been provided as a component part of the finishedduplicate, and which bears on one side an adhesive 6 holding insuspension suitable chemical agents for fixing the image in emulsion 4,is now moistened by any means at hand and is made to adhere permanentlyto exposed emulsion 4 on print 3 by holding the surfaces in intimatecontact by pressure, or by squeegeeing, until the adhesive has set.Moistening adhesive 6 not only effects a permanent bond between sheets 3and 5, it also wets the chemical agents suspended in the adhesive andmakes possible a chemical reaction between the light-sensitive emulsionand the fixing agents, which reaction brings to an end further actionupon the emulsion by the light.

The duplicate when thus completed, comprises a transparent lm supportingan emulsion which bears an image of the original, held in permanent bondwith a strong and durable second sheet by an adhesive impregnated withfixing agents, in such a manner that the emulsion and xing agents areenclosed between the inner surfaces of film and second sheet.

Although a translucent film or emulsion may be satisfactory for thepurpose of exposing the print, it is nevertheless necessary to have atransparent film on the duplicate. Emulsion 4 has been in contact withoriginal 1, and if the duplicate is to be an obverse of the original,

the image must be viewed through the film. Further, the emulsion beingon the reverse side of the film, permanent contact between emulsion andfixing agents becomes immediately possible; whereas, any other relativelocation of the emulsion would require the use of special equipment forfixing the image before it could be bonded to the second sheet. l

The method of printing used in this embodiment of the invention is wellknown in the photographic arts, and is variously termed reflectography,reflex printing, irradiation printing, and Contact printing, althoughthe latter term is applied to all printing wherein contact is madebetween the print and original-usually a negative in photography-whetherthe light is transmitted through the original or reflected from thesurface thereof. The principle underlying these methods of printing isillustrated in illustration C of Fig. 3. Film 3 has been placed injuxtaposition on the original 1 with the emulsion 4 in contact with theface of the original, as described above, and exposed to light. Assumingrays of light 7d and 71' to be approximately parallel, rays 7r passthrough transparent film 3 and are reflected back from the white surfaceof original 1, and again react upon the light sensitive emulsion. Thusrays 71' have a greater effect upon the emulsion than rays 7d which passthrough the emulsion and are absorbed by the dark surface of printedcharacter 2. The duplicate is therefore the reverse of the original asto high-lights and shadows, when the usual type of printing-out emulsionis used, although this need not necessarily be the case in allinstances.

I have eliminated the need for special equipment for fixing the image inthe emulsion by suspending the fixing agents in adhesive 6 which iscoated on one side of sheet 5. It has been the customary practice in thephotographic arts to fix prints with an excess of chemical agents andthen wash away the residue as a final step in the procedure. The onlyapparent reasons for this procedure are: it fits in with, and becomes asimilar part of the successive steps taken to develop the latent imagein developing-out processes, and toning in printing-out processes,wherein each print may require different treatment because of thereasons already described; and it provides an excess of chemicals tocompensate for changes in concentration of the solutions as successiveprints are made. According to my invention, however, where a definitequantity of light is known to have acted upon the emulsion, it has beenfound that the relative amounts of light and dark areas on the print canbe approximated closely enough to permit calculation of the amounts offixing agents actually required to fix the image. There is, in otherWords, a molecular balance between the substances comprising thelight-sensitive elements and those comprising the fixing agentssuspended in the adhesive of the second sheet. The exact amounts ofchemical agents being thus provided as component parts of the finishedduplicate, no skill is required to properly proportion them during themaking of the duplicate, no judgment is required in the degree oftreatment, and no equipment is necessary that is not commonly found inbusiness ofiices.

There is a time element in the fixing of prints in the usual processeswherein an excess of chemical agents are used, which time element alsoobtains in my method of fixing prints. However, I find that the actiondue to light ceases, within the limits permissible in highly contrastingprints, upon the application of the fixing agents suspended in theadhesive. The chemical reaction is not instantaneous, but rather extendsover an appreciable length of time, although not as long as may berequired when a print is fixed and developed in excess of chemicalagents. Since the amount of fixing agent has been calculatedto-molecularly balance the light-sensitive elements, and the chemicalaction eventually ceases; and

since action due to light receives its greatest retardation '6 at thetime of application of the xing agents, very little change in theappearance of the print, `due to action of light, takes place after ithas been placed in contact with the second sheet. Any slight change thatdoes occur after application of the second sheet accentuates the depthof tone, which is a desirable result.

To better explain the effects of the retardation of the action of lightand the gradual cessation of the fixing process, it should be noted thatone characteristic of all printing-out processes, especially those usingsilver chloride as the light-sensitive element, is the slowness of thereaction to light in comparison to the speed obtained in developing-outprocesses which utilize silver bromide as the active element. Thischaracteristic slowness of printing out emulsions allows an appreciableamount of time in which the exposed prints may remain in subdued lightwithout perceptible change in the appearance of the image. For example,an emulsion adapted to be printed in sunlight-as are emulsions usedcommercially by photographers for making proofs-may be sufficientlyprinted in one to two minutes when exposed to direct sunlight, but willremain perceptibly unchanged for many hours in a sunlit but shaded room.This characteristic quality of printing-out emulsions, together withthat of the almost complete suspension of the action of light uponapplication of the xing agents, makes printing-out emulsions especiallyadaptable to the objectives of this invention by eliminating thenecessity for dark rooms and dark cabinets.

In general it may be stated that the embodiment of this inventiondescribed above in detail comprises a lightsensitive, printing-outemulsion supported by a transparent lm, to which is attached anindicator having the exact color and tone of the emulsion when saidemulsion is sufficiently exposed to light; the film being then placedover the original with the emulsion in Contact with the original, andthe whole exposed to a suitable source of light until printed to thecolor and tone of the indicating element, regardless of the length oftime required because of the quality and intensity of the light; theexposed print being then removed from exposure to light, from contactwith the original, and from the indicating element which is of nofurther use; the print being then placed upon a fiat surface with theemulsion side uppermost, a second sheet is permanently bonded to thefilm by an adhesive'whichholds in suspension suitable chemical agentsfor fixing the image in the emulsion; the linished duplicate comprisingan exposed film in complete and permanent contact with a strong anddurable second sheet, and enclosing between them the exposed emulsion inmolecular balance with the fixing agents.

Although the above embodiment of this invention has proved satisfactoryin all respects, I have also found that many variations may be made inmaterials and procedure without departing from the spirit thereof. Asexamples of such variations, I find that instead of applying alightsensitive emulsion to a supporting base, the light-sensitiveelement may be incorporated in the base itself. This can bedone with theusual gelatin emulsions by first forming a comparatively hard and toughfilm of gelatin by the use of alum, alum compounds, and solutions offormaldehyde, as is commonly done in the photographic art; then coatingthis film with the sensitized emulsion and adding a final layer of thehard, tough gelatin to form a protective surface. The light-sensitiveelement is then within the body of the film instead of being on it. Inother instances, well known in the art, light-sensitive elements may beincorporated in the material comprising the base, and for the purposesof this invention, the sensitive element may be in, or on, thesupporting base. Another modication of the means to support thesensitive emulsion is to provide a rm base to support said sensitiveemulsion, which may be stripped from the emulsion either before or afterexposure. In this case, the base merely supports the sensitive filmprior to use, and

prevents injury to the film when packaging and handling, and does notbecome a part of the finished duplicate.

Another variation in the general procedure is in the application of thefixing agents. The colors of printingout emulsions are changed duringreaction with the fixing agents. In the event the resulting colors areunattractive, or otherwise unsuitable, they can be altered by the use ofchemical agents known as toners. It is commonly known that toners andxing agents may be combined in the same solution and appliedsimultaneously. The method used in an embodiment of this inventionwherein toner is to be used, has been to mix the toner and fixing agentsin the proper, predetermined proportions and suspend them in theadhesive of the second sheet which, when moistened, brings them intosolution. In the commercial use of the products of this invention, it isoften desirable to provide toners which will produce a choice of colorswithout the necessity of changing the other constituents of the finishedduplicate. in such cases,

I find it feasible to provide the required toner in solution as one ofthe component parts of the finished duplicate, and using it instead ofwater to meisten the ad hesive. The end results are the same, and avariety of tones and colors may be obtained with a minimum ofconstituent parts.

Still another variation in the use of the products of this inventionconcerns the use of the second sheet. Heretofore, this has beendescribed as a firm and durable component. Instead, this may be adelicate, transparent film which is coated with adhesive and fixingagents; in which case, the film supporting the sensitized emulsion maybe correspondingly firmer and more durable. This procedure is especiallydesirable when the duplicate must be transparent.

There are many chemical compositions of light-sensitive materials andmany methods of applying them according to this invention. The followingprocedures are described in detail as being typical and illustrative ofthe fundamentals and principles underlying this invention.

One example of the procedure embodying this invention may be performedentirely with materials obtainable from tradesmen dealing inphotographic materials in the usual course of business. Printing-outpaper, known to photographers as proof paper, is usually produced bycoating an emulsion of silver chloride in gelatin on a supporting baseof opaque paper. It is to be understood that although silver chloride isthe light sensitive element in a gelatin vehicle, other ingredients maybe added to procure certain desirable results such as speed of exposure,color, and to balance molecularly the toning and fixing agents, all ofwhich are well known and used in the art. When such a commercialemulsion is coated on a transparent film, it possesses all thecharacteristics necessary to sheet 3, described herein. After exposure,this emulsion can be toned and fixed with commercial preparations knownin trade channels as toners and fixing salts. The predominantconstituent of the fixing salts is sodium thiosulphate and this may beused alone to effect a satisfactory fixation of the image, without theuse of the other ingredients common to the commercial preparations.

When prints are fixed with sodium thiosulphate, the color of theemulsion changes to a disagreeable yellow hue. Hence, prior to fixing,and after exposure, it has been the practice to treat the emulsion witha solution of gold chloride; the gold replacing the silver in theemulsion and producing a pleasing dark purple tone, almost black.

if the toner and fixing agents are combined in one solution, asmentioned before, toning and fixing will take place simultaneously withan excess of both agents. According to this invention, the toning andfixing agents are suspended in the adhesive 6 of sheet 5 in properamounts to toneand fix the lightsensitive elements ol emulsion 4.Although such exact amounts are preferred,

8 actually a slight excess of either toner or fixing salts will have noinjurious effect upon the materials comprising the finished duplicate,nor on the final color or density of the print.

A similar example may be performed without the use of commercialpreparations, but with the basic chemical elements and compounds. Alight-sensitive emulsion is prepared by dissolving ammonium chloride,sodium chloride, and ammonium citrate in water in the proportions, byweight, 6 :3:10, respectively, to form a normal solution. This solutionis then mixed with gelatin which has been dissolved in water in theproportion, by weight, 3:44, respectively. To this gelatin-chloridemixture, a solution of silver nitrate is then added in sufficient amountto chemically react with the chlorides whereby silver chloride is formedas a precipitate; the silver chloride being the light-sensitive element.A slight excess of silver nitrate is often considered beneficial toprinting-out emulsions, as are other ingredients which are indicated bythe skiil and knowledge of the emulsion maker in bringing about certaindesirable results. The emulsion having been coated on one side of thetransparent film, or other supporting base, and exposed to light asheretofore described, toning and fixing complete the process. Goldchloride produces a satisfactory color in silver emulsions, althoughplatinum and tungsten and other metals may oe used instead. Sodiumthiosulphate being the fixing agent, it is combined with the goldchloride and certain ancillary ingredients in the following proportions,by weight; gold chloride l, citric acid 20, ammonium thiocyanate 40,alum 20, lead nitrate 22, lead acetate 22, and sodium thiosulphate 20.The procedure used in compounding these ingredients is well known in theart. However, it must be understood that my procedure is to susend allor part of the ingredients in the adhesive on the second sheet, orotherwise incorporate these ingredients iu the adhesive, as bymoistening the adhesive with water containing such ingredients.

i find that suitable adhesives have already been provided and areavailable in the customary trade channels. Illustrations of the generalnature of such adhesives may be had from the following descriptions: (l)An adhesive known commercially as envelope gum is made by dissolving gumarabic, sugar, and starch in warm water in the proportion, by weight,114:1, respectively. Dextrine may be substituted for gum arabic, andglucose for sugar, with boric acid added as stiffener, with equally goodresults. (2) Rice water boiled to a suitably thick jelly is inert to thechemical agents used herein, and is otherwise a suitable adhesive forthis process. (3) Gum arabic, gum tragacanth, and glycerin mixed in theproportions, by weight, 4:114, respectively, is quite satisfactory whereopaque adhesives are permissible. (4) One application of the products ofthis invention requires that the second sheet be a metal plate. In thiscase, the adhesive may be made of gum arabic, gum tragacanth, andglycerin, as above, with the addition of thymol in the proportions, byweight, 4: l :4:.l4, respectively.

While the above adhesives illustrate that the most common materials canbe used in this method of making duplicates, actually, the best adhesivematerial is the gelatin of the emulsions. In this procedure, thelightsensitive emulsion is prepared and applied as described herein. Thetoning and fixing agents are dissolved in gelatin and applied to thesecond sheet, after which the gelatin coat is treated with glycerin toproduce a tacky surface. When the second sheet is to be applied to theprint, the gelatin is moistened and the print pressed on to the secondsheet, the gelatin of the print and the gelatin of the second sheetbecoming one homogeneous substance.

When printing duplicates of printed pages of books and loose sheets, itis necessary that the print be in close and complete contact with thesurface of the original. if at any point close contact is not made, adispersion of light at that area will render the image indistinct. One

method of holding the film in close contact while print'- ing, which canbe used successfully with gelatin emulsions, is to form a soft layer ofgelatin that has been treated With glycerin, over the sensitizedemulsion. This soft layer of gelatin, shown at 9 in Fig. 2, will remaintacky over a long period of time and will adhere to the surface of paperand most other materials, and may be withdrawn from contact withoutleaving a perceptible trace of gelatin on the original. In packaging forcommercial purposes, the tacky side of the film is placed against aprotective sheet which is discarded when a print is to be made.

While I have described in considerable detail certain typicalillustrative embodiments of my invention shown in the accompanyingdrawings, it is to be understood that my invention is not limited tothese particular embodiments but include such modifications thereof asfall within the scope of the appended claims.

I claim:

1. lThe process of making a duplicate of an original which comprisesplacing on the surface of the original a transparent film carrying alight-sensitive printing-out emulsion with the emulsion in contact withthe original, exposing the thus covered original to light through thetransparent film and the printing-out emulsion carried thereby until thefilm acquires an image of the original of the desired intensity,removing the film from the original, and bonding to the film a layer ofsheet material carrying an adhesive having incorporated therein chemicalfixing agents for fixing said emulsion to stabilize the image, saidadhesive contacting said emulsion.

2. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original a transparent filmcarrying a light-sensitive printing-out emulsion, exposing the thuscovered original to light through the transparent film and theprinting-out emulsion carried thereby until the film acquires an imageof the original of the desired intensity, removing the film from theoriginal, and bonding to the film a layer of sheet material carrying anadhesive having incorporated therein chemical fixing agents for fixingsaid emulsion to stabilize the image, said adhesive contacting saidemulsion and being of such character as to form a substantiallypermanent bond therewith, whereby a laminated structure having theexposed and stabilized printing-out emulsion secured between said filmand said layer of sheet material is obtained.

3. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original an unexposedtransparent film carrying a light-sensitive printing-out emulsion andalso carrying a color gauge having the tone and color of the emulsionafter the emulsion has been adequately exposed to light, exposing thethus covered original to light through the transparent film and theprinting-out emulsion carried thereby until the film acquires an imageof the original having its color and tone matching that of the colorgauge, removing the film from the original, and bonding to the film alayer of sheet material carrying an adhesive having incorporated thereinchemical fixing agents for fixing the said emulsion to stabilize theimage, said adhesive contacting said emulsion and being of suchcharacter as to form a substantially permanent bond therewith, whereby alaminated structure having the exposed and stabilized printing-outemulsion secured between said film and said layer of sheet material isobtained.

4. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original an unexposedtransparent film carrying a light-sensitive printing-out emulsion andhaving a color gauge detachably xed to the marginal portion of the film,said color gauge having the color and tone of the emulsion after theemulsion has been adequately exposed to light, exposing the thus coveredoriginal to light through the transparent film and the printing-outemuli sion carried thereby until the film acquires an image of theoriginal having its color and tone matching that of the color gauge,removing the film from the original, detaching the color gauge, andbonding the film to a layer of sheet material carrying an adhesivehaving incorporated therein chemical fixing agents for fixing saidemulsion to stabilize the image, said adhesive contacting said emulsionand being of such character as to form a substantially permanent bondtherewith, whereby a laminated structure having the exposed andstabilized printing-out emulsion secured between saidfilm and said layerof `sheet material is obtained.

5. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original an unexposedtransparent film carrying a light-sensitive printing-out emulsion,exposing the thus covered original to light through the transparent filmand the printing-out emulsion carried thereby until the film acquires animage of the original of the desired intensity, removing the film fromthe original, and bonding the film to a layer of sheet material carryingan adhesive having incorporated therein chemical toning and fixingagents for toning and fixing said emulsion, said adhesive contactingsaid emulsion and said image being stabilized, said adhesive being ofsuch character as to form a substantially permanent bond with saidemulsion, whereby a laminated structure having the exposed andstabilized printing-out emulsion secured between said film and saidlayer of sheet material is obtained.

6. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original an unexposedtransparent film carrying a lightsensitive printing-out emulsion and alayer of tacky material for temporarily holding the film in intimatecontact with the original, exposing the thus covered original to lightthrough said transparent film and the printingout emulsion carriedthereby until the film acquires an image of the original of the desiredintensity, removing the film from the original, and bonding the film toa layer of sheet material carrying an adhesive having incorporatedtherein chemical fixing agents for fixing said emulsion to stabilize theimage, said adhesive contacting said emulsion and being of suchcharacter as to form a substantially permanent bond therewith, whereby alaminated structure having the exposed and stabilized printing-outemulsion secured between said film and said layer of sheet material isobtained.

7. The process of making a duplicate of an original which consistsessentially of placing on the .surface of the original an unexposedtransparent lm carrying a light-sensitive printing-out emulsion and alayer of glycerine-treated gelatin providing a tacky surface in contactwith the original, exposing the thus covered original to light throughsaid transparent film and the light-sensitive emulsion carried therebyuntil the film acquires an image of the original of the desiredintensity, removing the film from the original, bonding to the film alayer of sheet material carrying an adhesive having incorporated thereinchemical fixing agents for fixing said emulsion to stabilize the image,said adhesive contacting said emulsion and being of such character as toform a substantially permanent bond therewith, and applying moisture toactivate the chemical fixing agents prior to the bonding of said layerto said film, whereby a laminated structure having the exposed andstabilized printing-out emulsion secured between said film and saidlayer of sheet material is obtained.

8. The process of making a duplicate of an original which comprisesplacing on the surface of the original a transparent film carrying asilver-salt light-sensitive printing-out emulsion with the emulsion incontact with the original, exposing the thus covered original to lightthrough the transparent film and the printing-out emulsion carriedthereby until the film acquires an image of the original. of the'desiredintensity, removing the film from the original, bonding to the film alayer of sheet material carrying an adhesive having incorporated thereinchemical xing agents for xing said emulsion to stabilize the image, saidadhesive contacting said emulsion, and applying moisture to activate thechemical fixing agents prior to bonding said layer to the film.

9. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original a transparent iilmcarrying a silver-salt light-sensitive printing-out emulsion, exposingthe thus covered original to light through the transparent lm and theprinting-out emulsion carried thereby until the lm acquires an image ofthe original of the desired intensity, removing the lm from theoriginal, bonding to the lm a layer of sheet material carrying anadhesive having incorporated therein chemical fixing agents for fixingsaid emulsion to stabilize the image, said adhesive contacting saidemulsion and being of such character as to form a substantiallypermanent bond therewith, and applying moisture to activate the chemicalfixing agents prior to the bonding of said layer to said film, whereby alaminated structure having the exposed and stabilized printing-outemulsion secured between said ilrn and said layer of sheet material isobtained.

10. The process of making a duplicate of an original which consistsessentially of placing on the surface of the original an unexposedtransparent iilm carrying a lightsensitive silver-salt printing-outemulsion and a layer ot' a tacky material for temporarily holding thenlm in intimate contact with the original, exposing the thus coveredoriginal to light through the transparent lm and the printing-outemulsion carried thereby until the iilm acquires an image of theoriginal of the desired intensity, removing the ilm from the original,bonding the film to a layer of sheet material carrying an adhesivehaving incorporated therein chemical xing agents for xing said emulsionto stabilize the image, said adhesive contacting said emulsion tostabilize the image, said adhesive contacting said emulsion and being ofsuch character as to form a substantially permanent bond therewith, andapplying moisture to activate the chemical ixing agents prior to thebonding of said layer to said lm, whereby a laminated structure havingthe exposed and stabilized printingaout emulsion secured between saidilm and said layer of sheet material is obtained.

References Cited in the tite of this patent UNlTED STATES PATENTS560,755 Schoenfelder May 26, 1896 725,525 White Apr. 14, 1903 770,421Derepas Sept. 20, 1904 1,565,256 Christensen Dec. 15, 1925 1,939,026Spencer et al Dec. 12, 1933 2,001,951 Berry May 21, 1935 2,018,195Thornton Oct. 22, 1935 2,018,196 Thornton Oct. 22, 1935 2,036,369Simjian Apr. 7, 1936 2,083,675 Ville June 15, 1937 2,244,304 MarriageJune 3, 1941 2,341,461 Matthews Feb. 8, 1944 2,409,564 Heinecke Oct. 15,1946 FOREIGN PATENTS 9,248 Great Britain of 1905 24,667 Great Britain of1906 331,154 Great Britain June 26, 1930 471,366 Great Britain Sept. 2,1937 101,668 Austria Nov. 25, 1925 138,389 Austria July 25, 1934 141,872Austria May 25, 1935 115,331 Switzerland June 16, 1926

1. THE PROCESS OF MAKING A DUPLICATE OF AN ORGINAL WHICH COMPRISESPLACING ON THE SURFACE OF THE ORIGINAL A TRANSPARENT FILM CARRYING ALIGHT-SENSITIVE PRINTING-OUT EMULSION WITH THE EMULSION IN CONTACT WITHTHE ORGANIAL, EXPOSING THE THUS COVERED ORIGINAL TO LIGHT THROUGHT THETRANSPARENT FILM AND THE PRINTING-OUT EMULSION CARRIED THEREBY UNTIL THEFILM ACQUIRES AN IMAGE OF THE ORIGINAL OF THE DESIRED INTENSITY,REMOVING THE FILM FROM THE ORIGINAL, AND BONDING TO THE FILM A LAYER OFSHEET MATERIAL CARRYING AN ADHESIVE HAVING INCORPORATED THEREIN CHEMICALFIXING AGENTS FOR FIXING SAID EMULSION TO STABILIZE THE IMAGE, SAIDADHESIVE CONTACTING SAID EMULSION.